Detectors and sensors of all different types are utilized in virtually every walk of life. The miniaturization and efficiency of any sensor is a continuous goal for device designers. Stated alternatively, it is almost always beneficial to design and develop sensors and detectors which are more efficient and which can be packaged as smaller devices. By developing small efficiently operating sensors, various additional applications are typically made possible. This is specifically applicable to sensors which detect different types of radiation.
One known method for detecting radiation is by means of optical detectors that convert a photon into an electron via electron/hole generation upon impact of a photon in a generation/recombination zone. The sum of the electrons/holes generated by the photons represents a signal current that corresponds to the received optical power. This is equivalent to the number of photons incident to the detector that are actually converted to electrons. The conversion is typically done in a photo diode.
Another way of converting light involves treating the light signal as an electromagnetic wave and detecting via antennas or absorbing area. In an antenna coupled Bolometer, the energy of the electromagnetic wave received by the antenna is absorbed in a sensor element, which leads to an increase in temperature in the sensor element. The change in temperature causes a change in the electrical properties of the sensor element (e.g. a change in electrical resistance or change of the tunneling current in a semiconductor).
Existing CMOS based sensors, which are effective for their given purposes, allows for the generation of the far-infrared bolometer. Far-infrared bolometers of many different types presently exist, however they are not efficiently designed for speed and responsiveness.
Using a frequency selective antenna, a bolometer which responds to radiation of a particular frequency can be envisioned. That is, the bolometer is designed to detect a prescribed frequency of radiation, and then produce an appropriate output signal. Using an array of different sized antenna coupled bolometers, a wide frequency range can be covered. Typically, these revised devices are spectrometers, which are useful for many different applications. Spectrometers are typically utilized to detect wide band spectral characteristics. A spectrometer is particularly useful, and essential, for chemical analysis in many types of areas.
As such, there is a need for compact spectrometers, which can easily be implemented in microelectronic chip format. Further, there is a need for a compact spectrometer which is efficient and responsive to a broad spectrum of radiation.